Superlubricity Achieved with Mixtures of Acids and Glycerol

作者:Li, Jinjin; Zhang, Chenhui*; Ma, Liran; Liu, Yuhong; Luo, Jianbin
来源:Langmuir, 2013, 29(1): 271-275.
DOI:10.1021/la3046115

摘要

In this work, superlubricity between glass and Si3N4 surfaces lubricated by mixtures of acid solutions and glycerol solutions has been found by using a traditional tribometer. Ultra low friction coefficients of between 0.004 and 0.006 were obtained after a running-in period. Related experiments indicate that the hydrogen ions in the mixtures play an important role in achieving superlubricity. Moreover, the ultralow friction is also closely related to the pH value of the acid and the concentration of glycerol. According to these results, the possible superlubricity mechanism has been revealed, which is attributed to a fluid-hydrated water layer between the hydrogen-bonded networks of glycerol and water molecules on the positively charged surfaces.